Reduce to lowest terms: $- \dfrac{8}{7} \div - \dfrac{6}{5} = {?}$
Explanation: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $- \dfrac{6}{5}$ is $- \dfrac{5}{6}$ Therefore: $ - \dfrac{8}{7} \div - \dfrac{6}{5} = - \dfrac{8}{7} \times - \dfrac{5}{6} $ $ \phantom{- \dfrac{8}{7} \times - \dfrac{5}{6}} = \dfrac{-8 \times -5}{7 \times 6} $ $ \phantom{- \dfrac{8}{7} \times - \dfrac{5}{6}} = \dfrac{40}{42} $ The numerator and denominator have a common divisor of $2$, so we can simplify: $ \dfrac{40}{42} = \dfrac{40 \div 2}{42 \div 2} = \dfrac{20}{21} $